Method and apparatus for environmental protection of drive-over tire tread depth optical sensors

Abstract

A drive-over tire tread depth measurement system is configured with environmental protection components for preventing or impeding environmental contaminates from falling through openings in a vehicle support surface or cover plate onto underlying components such as sensor optical windows and adjacent surfaces. The environmental protection components may include air discharge assemblies, movable shields, guards, wipers or deflectors such as drip edges, water-accumulating textured surfaces, flow diverters, and selectively placed flanges or fixed guards which operate cooperatively to displace accumulated contaminates, debris, or liquids from the optical windows and adjacent sensor surfaces. A portion of the vehicle support surface or cover plate is removable to permit access to underlying components.

The invention claimed is: 
     
       1. A drive-over optical tire tread depth sensor system, comprising:
 a vehicle support surface configured to support a wheel assembly, said vehicle support surface including an opening; 
 a sensor housing containing an optical component disposed in proximity disposed relative to, and spaced from, an underside of said vehicle support surface, said optical component having an optical axis or field of view aligned to pass through said opening at an acute angle; 
 wherein said sensor housing is biased towards said underside of said vehicle support surface; and 
 wherein at least a portion of said vehicle support surface is removable for access to said optical component. 
 
     
     
       2. The system of  claim 1  wherein said optical component is a laser, and said optical axis is a laser projection axis. 
     
     
       3. The system of  claim 1  wherein said optical component is an imaging sensor and said field of view is an optical imaging sensor field of view. 
     
     
       4. The system of  claim 1  wherein said optical component is offset along a longitudinal axis of the sensor system from said opening in said vehicle support surface through which said associated optical axis or field of view passes, such that said optical component is not in vertical alignment with said opening. 
     
     
       5. The system of  claim 1  further including least one deflecting surface associated with said opening, said deflecting surface configured to deflect, away from said optical component, environmental contaminates and debris descending through said opening. 
     
     
       6. The system of  claim 1  wherein said sensor housing further includes a second optical component laterally adjacent to and aligned with said optical component, said second optical component having a second optical axis or field of view;
 wherein said vehicle support surface further includes a second opening associated with said second optical axis or field of view; and 
 wherein said second optical component is disposed relative to, and spaced apart from said underside of said vehicle support surface, such that said second optical axis or field of view is aligned to pass through said second opening at an acute angle. 
 
     
     
       7. The system of  claim 1  wherein said sensor housing further includes a second optical component longitudinally adjacent to and aligned with said optical component, said second optical component having a second optical axis or field of view;
 wherein said vehicle support surface further includes a second opening associated with said second optical axis or field of view; and 
 wherein said second optical component is disposed relative to, and spaced apart from said underside of said vehicle support surface, such that said second optical axis or field of view is aligned to pass through said second opening at an acute angle. 
 
     
     
       8. The system of  claim 1  further including a gutter disposed below said vehicle support surface, said gutter configured to prevent a flow or migration of accumulated environmental contaminates or debris from entering said optical axis or field of view. 
     
     
       9. The system of  claim 1  further including a cover plate mounted to the vehicle support surface, said cover plate surrounding said opening without interference with said optical axis or field of view passing through said opening; and
 wherein said cover plate is configured to divert environmental contaminates or debris away from said opening. 
 
     
     
       10. An improved drive-over optical tire tread depth measurement system having an optical component with an optical axis or field of view, the optical component disposed in spaced proximity to an underside of the vehicle support surface, said vehicle support surface having at least one opening in alignment with the optical axis or field of view, the improvement comprising:
 at least one environmental protection feature selected from a set of environmental protection features including a fixed fluid flow deflecting element within said at least one opening and an entrapping gutter below said at least one opening; and 
 wherein said at least one environmental protection feature is disposed to avoid interference with said optical axis or field of view. 
 
     
     
       11. The improved drive-over optical tire tread depth measurement system of  claim 10  wherein at least a portion of said vehicle support surface or cover plate is removable for access to said optical component. 
     
     
       12. The improved drive-over optical tread depth measurement system of  claim 10  wherein said fixed fluid flow deflecting element is configured to deflect, away from said optical component, environmental contaminates and debris entering through said opening. 
     
     
       13. The improved drive-over optical tread depth measurement system of  claim 10  wherein said entrapment gutter is configured to prevent accumulated environmental contaminates or debris from entering said optical axis or field of view. 
     
     
       14. The improved drive-over optical tread depth measurement system of  claim 10  wherein said at least one opening in said vehicle support surface or cover plate is longitudinally offset from said optical component. 
     
     
       15. A drive-over optical tire tread depth sensor system, comprising:
 an optical component having an illuminating laser optical axis and an optical imaging sensor field of view; 
 a vehicle support surface in spaced apart proximity above said optical component, said vehicle support surface having at least one opening in optical alignment with said optical axis and said field of view; and 
 an air discharge system disposed in proximity to said optical component, said air discharge system including at least one air discharge oriented to direct pressurized air to laterally displace environmental contaminates, debris or liquids accumulated between an underside of said vehicle support surface and said optical component from said optical axis or field of view. 
 
     
     
       16. The system of  claim 15  including a shutter assembly disposed between said underside of said vehicle support surface and said optical component, said shutter assembly having a shutter operable between a closed position adjacent said underside of said vehicle support surface and at least partially occluding said at least one opening in said vehicle support surface, and an open position in which said shutter is displaced away from said underside of said vehicle support surface and from said optical axis or field of view. 
     
     
       17. The system of  claim 16  wherein said shutter assembly includes an actuator configured to actuate said shutter between said closed position and said open position; and
 further including a control system configured with software instructions to regulate operation of said actuator by coordinating actuation with operation of said optical component. 
 
     
     
       18. The system of  claim 15  wherein said at least one air discharge is an air knife assembly having at least one air nozzle configured to provide a lateral discharge of air between said optical component and said underside of said vehicle support surface. 
     
     
       19. An improved drive-over optical tire tread depth sensor system having an optical axis or field of view associated with an optical component disposed in spaced apart proximity to an underside of a vehicle support surface having at least one opening in alignment with the optical axis or field of view, the improvement comprising:
 at least one environmental protection feature selected from a set of environmental protection features including a movable shutter disposed below said underside of said vehicle support surface and associated with said at least one opening, a fluid flow deflecting element on said vehicle support surface in proximity to said at least one opening, an entrapping gutter below said at least one opening, a wiper mechanism configured to sweep a wiper across said at least one optical axis or field of view, and an air discharge assembly for periodically discharging a flow or blast of pressurized air laterally across said at least one optical axis or field of view below said underside of said vehicle support surface. 
 
     
     
       20. A method for preventing an accumulation of environmental contaminates, debris, or liquids on a surface of a drive-over optical tire tread depth sensor system disposed in spaced proximity below an underside of a vehicle support surface having at least one opening in alignment with an illuminating laser optical axis or an optical imaging sensor field of view, comprising:
 activating an air discharge assembly disposed below said underside of said vehicle support surface to laterally discharge a flow of pressurized air beneath said underside of said vehicle support surface to laterally displace accumulated contaminates, debris, or liquids from said illuminating laser optical axis or said optical imaging sensor field of view.